Adjustable speed-gear.



No. 700,970. Patented May 27, |902.

J. D. MGFARLAND, In.

ADJUSTABLE SPEED GEAR. (Application filed Sept. 23, 1901.)

(No Model.)

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NTTED STATES PATENT OFFICE."

JAMES D. MCFARLAND, JR., OF SAN FRANCISCO, CALIFORNIA, ASSIGNOR OFONE-HALF TO JOHN BRUCKMAN, OF SAN FRANCISCO, CALIFORNIA.

ADJUSTABLE SPEED-G EAR.

SPECIFICATION .forming part of Letters Patent No. 700,970, dated May 27,1902. Application led September 23, 1901. Serial No. 76,208. (No modal.)

To all whom, it may concern:

Beit known that I, JAMES D. MCFARLAND, Jr., a citizen of the UnitedStates, residing in the city and county of San Francisco, State ofCalifornia, have invented an Improvement in Adjustable Speed-Gears; andI herebyfdeclare the following to be afull, clear, and exact descriptionof the same.

My invention relates to improvements in devices by which a variablespeed may be derived from a source of constant power. Its object is toprovide a mechanism that is simple in construction and easy ofmanipulation, suitable for use in automobiles or wherever a change ofspeed is frequently necessary and wherein it is not desirable'to dependon the engine to effect these changes. l

It consists, essentially, of a shaft, a sleeve slidable longitudinallythereon, helical grooves or tongues varying in pitch upon the peripheryof the sleeve, a clutch mechanism reeiprocable upon the sleeve, means bywhich said clutch is adapted toengage the tongues or grooves on saidsleeve and impart a rotary motion to the latter, and means whereby saidsleeve may be shifted so as to bring any portion of said grooves ortongues into such engagement.

It also comprises details which will be more fully set forthhereinafter, having reference to the accompanying` drawings, in which-Figure l is a side view of the mechanism. Fig. 2 is a cross-section ofthe same on line a; of Fig. l. Fig. Sis a View of a channeled guide.Fig. A.L is a modification of the device. A represents a shaft to whichit is desired to impart a variable speed in one direction. From thisshaft power may be transmitted, for example, to the axle B of anautomobile by means of the bevel-gear h, meshing with the shifting orreverse gearing b. A sleeve 2 is slidable in afeather 3 longitudinallyupon the shaft. This sliding movement of the sleeve may be effected asby means of a forked lever 4. Upon the periphery of the sleeve are thehelical tongues 5. The sleeve is devided by imaginary planesperpendicular to its axis into sections 5 5b 5 5d, dac., said sectionscorresponding in length approximately to the stroke length of the clutchC, which is reeiprocable upon the sleeve. Within each of these sectionsthe pitch of the tongues is uniform, but varies in relation to the pitchin all the other sections-that is, the pitch of the tongues, e. g., inthe section 5 at one end of the sleeve will be :nothing-z'. e., thetongues will extend in a straight line. In the succeeding `section 5bthe pitch maybe twenty degrees, in 5C forty degrees, 5d sixty degrees,and so on, the line of the tongues, however, being continuous and theprogression of increase or decreasebeing uniform. There are, in fact,two setsof these tongues, one winding to the right and one to the leftabout the sleeve. n

C is a clutch inclosingthesleeve and adapt ed to be reciprocatedbyaprime mover-,Where by a rectilinear moveinent of the clutch is'converted into a rotary movement of the sleeve and4 shaft. The manner inwhich this is effected isas follows: `The clutch yC is secured tothe rod"6, reciprocated from the prime mover, and consists'of a frame 7, inwhich are the rotatable members 8. The clutch is prevented from turningby means of the guides 9. These members are of any suitable form, thoughI have shown here by way of preference two rings having notches 10 ontheir peripheries. The walls of these notches are pitched oppositely inthe two rings. In the notches are balls 1l, which are adapted to bindagainst the'inner Wall of the frame when one or the other of the ringsis revolved in one way and to allow the ring to revolve freely in theframe when turned in the opposite direction. The diiference of directionof pitch of the notches in the rings allows one ring to revolve freelywhile the other is locked against the frame. On the inner periphery ofeach ring are recesses l2, corresponding in number to one set of tongueson the sleeve. In each recess is revolubly socketed a channeled guide orpin 13, which is adapted to engage one of the tongues, so that when therod 6 is reciprocated :in one direction this slotted pin'will by reasonof the non-turningof the clutch C and the engagement of the balls bywhich the ring is made rigid with the clutch-frame cause the sleeve andshaft A to turn. When the rod reverses its movement, the 4clutch movesin the opposite direction, the balls release their grip, and the ringrevolves freely within the frame and in unison with the sleeve andwithout retarding the latter. As the pins are loose in the sockets, theyare able to turn and aecommodate themselves to the sinuous line of thetongues, although the direction of travel of the pins is, like that ofthe clutch and rod, in a horizontal line. The pins in the other ring actsimilarly upon the other set of tongues, but on alternate reciprocationsfrom the first, so that power is being applied to the sleevecontinuously and at each reciprocation of the rod.

By means of the clutch-lever 4: the sleeve may be made to slide upon theshaft so as to bring any section 5a 5b, 85e., within the line of travelof the clutch. As each section has its tongues pitched to a certainrelative speed, the revolution of the sleeve and axle will be faster orslower, according to this pitch or ineline, while the speed of the primemover remains constant. Thus, for example, when theelutch C is actingover the surface of section 5ba speed, say, of two andone-half miles anhour would be indicated by the revolution of the sleeve and shaft. Thesection 5C would indicate five miles per hour, section 5d ten miles,&c., each section indicating a relative speed desired to be obtained.The section 5a has its tongues horizontal for the purpose of allowingthe sleeve and axle, and consequently the carriage which they maypropel, to be brought to a standstill without stopping the engine.

The advantage of such a variable-speed mechanism is apparent where themotive power isan explosive-engine and wherein there is always a directloss when it is attempted to obtain dierences of speed in the driveshaftby varying the speed of the engine. Furthermore, it is readilyseen thatthe sleeve may be made to act as a brake, if desired.

While I have spoken of the helical guides on the sleeve as tongues andthe pins 13 as being slotted, it is obvious that the relationship ofthese parts may be reversed, and the sleeve may have helical grooves,while the pins will be adapted to travel in these grooves, or, as inFig. 4:, the helical grooves 5 may be formed directly upon the shaft A',which is made slidable on a feather in a sleeve 2,which latter carriesthe transmitting-gear b2. Motion is imparted to the shaft by means ofthe clutch C', as in the first instance.

Having thus described my invention, what I claim, and desire to secu reby Letters Patent, is-

l. Adrivingmechanismcomprisingashaft, a sleeve on said shaft, helicalguides on said sleeve and of varying pitch, a clutch mechanism engagingsaid guides, and connections of said mechanism with a prime moverwhereby the clutch is reciprocated to drive the sleeve and shaft.

2. Inadriving mechanism, the combination of a shaft, a sleeve slidablethereon and turnable therewith, helical guides varying in pitch betweentheir ends upon said sleeve, and a clutch mechanism engaging said guidesand reciprocable in the line of the shaft.

3. In a driving mechanism, the combination of a shaft, asleeve slidablethereon and turnable therewith, helical guides of varying pitch on saidsleeve, part of said guides winding to the right and the remainder tothe left about said sleeve, and a clutch mechanism engaging said guidesand adapted to reciprocate in the line of the shaft.

4. In a driving mechanism, the combination of a shaft, a sleeve slidablethereon and turnable therewith, helical guides of varying pitch on saidsleeve, a clutch mechanism reciprocable in the line of the shaft, saidclutch having members engaging said guides, said members actingalternately to drive the sleeve and to revolve freely therewith, andmeans for shifting -said sleeve within said clutch mechanism.

5. In a driving mechanism the combination of a shaft, a sleeve slidablethereon and revoluble therewith,helical guides of varying pitch on saidsleeve, a clutch mechanism inclosing said sleeve, and reciprocablethereon, means by which said clutch is prevented from turning, andconnections between said clutch and guides whereby the sleeve and shaftare revolved.

6. In a driving mechanism, the combination of a shaft, a sleeve thereon,helical guides of varying pitch on said sleeve, a clutch inclosing andreciprocable upon said sleeve, means by which said clutchis preventedfrom turning, said clutch comprising rotatable members, pins socketed insaid members, said pins adapted to engage the helical guides to drivethe sleeve and shaft when the clutch is reciprocated.

7. In a driving mechanism, the combination of a shaft, a sleeve thereon,helical guides of varying pitch on said sleeve, a clutch inclosing andreciprocable upon said sleeve, said clutch comprising a frame, rotatablegrip members in said frame, recesses on the inner periphery of saidmembers, pins loosely socketed in said recesses, and said pins adaptedto engage the helical guides to drive the sleeve and shaft.

8f In a driving mechanism, the combination of a shaft, a sleeve thereon,helical guides of varying pitch on said sleeve, a clutch inclosing andreciprocable upon said sleeve, means by which said clutch is preventedfrom turning, said clutch having grip members rotatable in oppositedirections, and pins carried by said members and adapted to engage thehelical guides to drive the sleeve when the clutch is reciprocated.

9.' A driving mechanism consisting in combination of a shaft, a sleeveslidable thereon and revoluble therewith, helical guides on `saidsleeve, .said guides having a uniform progressive variance in pitchbetween their ends, a clutch inclosing and reciprocable upon saidsleeve, means by which said clutch is prevented from turning, rotatablegrip members in said clutch and means upon said members IOO IIO

1o able in relation to the other, helical guides of varying pitch onsaid slidable member, and a reciprocable clutch mechanism engaging saidguides.

In Witness whereof I have hereunto setm hand.

JAMES D. MCFARLAND, JR.

Witnesses:

' IS. H. NOURSE,

JEssIE C. BRonIE.

